feat: schema store support

[Vincent Biret (baywet)]

closes #325970 depends on #327104

[vs-code-engineering]

📬 CODENOTIFY

The following users are being notified based on files changed in this PR:

Raymond Zhao (@rzhao271)

Matched files:

• src/vs/workbench/contrib/preferences/common/settingsFilesystemProvider.ts

[Copilot]

Pull request overview

Adds dynamic JSON validation registries and SchemaStore catalog support to the JSON language features extension.

Changes:

• Registers and validates the jsonValidationRegistry contribution point.
• Loads, watches, and refreshes local and remote schema registries.
• Converts internal schema associations to catalog format.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
extensionPoints.json	Registers the contribution point.
extensionManifestPropertiesService.ts	Allows it in the Sessions window.
settingsFilesystemProvider.ts	Emits catalog-formatted associations.
jsonValidationExtensionPoint.ts	Defines and validates registry contributions.
AI_CUSTOMIZATIONS.md	Adds unrelated migration documentation.
extensions.ts	Adds contribution manifest types.
package.json	Contributes local and SchemaStore registries.
jsonClient.ts	Loads, watches, and refreshes registries.

Comments suppressed due to low confidence (3)

extensions/json-language-features/client/src/jsonClient.ts:559

• The generation check only suppresses a stale notification; getSchemaAssociations(true) replaces the shared cache before the request finishes. If an older refresh completes after a newer one, it overwrites schemaAssociationsCache with stale extension/registry data even though its notification is skipped. Compute into a local value and commit both the cache and notification only for the current generation.

			const associations = await getSchemaAssociations(true);
			if (generation === schemaAssociationRefreshGeneration) {
				client.sendNotification(SchemaAssociationNotification.type, associations);
			}

extensions/json-language-features/client/src/jsonClient.ts:890

• SchemaStore catalog entries are forwarded as ordinary associations. The dependent vscode-json-languageservice#342 change only gives explicit $schema and configured schemas precedence when an association has source: 'schemaStore'; without that marker, catalog schemas can be combined with explicit/configured schemas and produce conflicting diagnostics. Preserve a registry kind/source through the contribution API and emit it here, while leaving the dynamic vscode://schemas-associations registry as a normal association.

						result.push({
							fileMatch: schema.fileMatch,
							uri: schema.url
						});

extensions/json-language-features/client/src/jsonClient.ts:862

• registrys is a misspelling and makes the collection name harder to scan. Use the standard plural registries consistently.

		const registrys = extension.packageJSON?.contributes?.jsonValidationRegistry;
		if (Array.isArray(registrys)) {
			for (const registry of registrys) {